The invention concerns a tank venting filter comprising a housing that is extending in the direction of its longitudinal filter axis and comprising a filter element arranged in the housing.
When from a tank, for example, a fuel tank or urea tank of a motor vehicle, a liquid is removed, the tank must be vented in order to avoid underpressure within the tank. The tank venting device enables sucking in ambient air into the tank upon removal of the liquid. When sucking in the ambient air, foreign matter, in particular dust, dirt or water, may however pass into the tank. Primarily when driving in rain, high water introduction may occur. In order for the foreign matter not to reach the tank, the tank venting device has in general a tank venting filter. Such a tank venting filter is the subject matter of the present invention.
U.S. Pat. No. 3,546,853 A discloses a filter extending in longitudinal direction which has intake openings at its bottom side. A filter element introduced into the filter is substantially cylindrical. Inflow of the medium to be filtered occurs against the outer cylindrical wall surface of the filter element.
GB 773 490 A discloses an intake device for a liquid. Upon sucking in the liquid, air is sucked in at the top side of the intake device. In the intake device, a filter element for filtering the liquid is provided.
Finally, US 2006/0081634 A1 discloses a filter for a tank venting device. The filter has air inlets at the top side. The connecting socket to the tank is embodied at the bottom side of the filter.
The filters known from the prior art have the disadvantage that the filter elements in the filter clog relatively quickly with dust, dirt, or water.
It is the object of the present invention to provide a constructively simple tank venting filter whose filter element will clog significantly more slowly with dust, dirt or water.